Abstract

This grant application is aimed at establishing a link between the fine structure of the gap junction channel wall and channel permselectivity. The investigators propose to study the properties of rat Cx26, Cx32, Cx37, Cx40, Cx43 and Cx46 when expressed in transfected N2A cells. They will analyze the spread of anionic fluorescent probes via estimations of three basic parameters: cytoplasmic diffusion coefficient, junctional membrane permeability and leak permeability. The second specific aim is to transfect mouse N2A cells with mutant versions of the connexins studied under Specific aim 1, and to evaluate the same permeability parameters. Through these studies, the investigators propose to locate the site(s) that constitute the anionic filter. The mutagenesis analysis will focus on the four transmembrane domains, and the two extracellular loops.
Under specific aim three, the applicants will use the dual whole cell patch clamp technique to verify the existence of gap junction channels and, if channels are found, to determine the unitary conductance and the cation/anion permeability properties of the mutant under study. Finally, under specific aim four, the investigators propose to characterize a relation between channel properties and dye transfer. The latter may allow for determination of permeability of large anions at the channel level.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM055263-04S1
Application #
6474469
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Program Officer
Shapiro, Bert I
Project Start
1997-05-01
Project End
2002-07-31
Budget Start
2000-05-01
Budget End
2002-07-31
Support Year
4
Fiscal Year
2001
Total Cost
$67,544
Indirect Cost

  Institution

Name
State University New York Stony Brook
Department
Physiology
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794

  Publications

Ross, Christina L; Siriwardane, Mevan; Almeida-Porada, Graça et al. (2015) The effect of low-frequency electromagnetic field on human bone marrow stem/progenitor cell differentiation. Stem Cell Res 15:96-108
Mese, Gulistan; Valiunas, Virginijus; Brink, Peter R et al. (2008) Connexin26 deafness associated mutations show altered permeability to large cationic molecules. Am J Physiol Cell Physiol 295:C966-74
Yum, Sabrina W; Zhang, Junxian; Valiunas, Virginijus et al. (2007) Human connexin26 and connexin30 form functional heteromeric and heterotypic channels. Am J Physiol Cell Physiol 293:C1032-48
Brink, Peter R; Valiunas, Virginijus; Wang, Hong-Zhan et al. (2006) Experimental diabetes alters connexin43 derived gap junction permeability in short-term cultures of rat corporeal vascular smooth muscle cells. J Urol 175:381-6
Wang, H-Z; Brink, Peter R; Christ, George J (2006) Gap junction channel activity in short-term cultured human detrusor myocyte cell pairs: gating and unitary conductances. Am J Physiol Cell Physiol 291:C1366-76
Rosen, Michael R (2005) 15th annual Gordon K. Moe Lecture. Biological pacemaking: in our lifetime? Heart Rhythm 2:418-28
Ramanan, S V; Valiunas, V; Brink, P R (2005) Non-stationary fluctuation analysis of macroscopic gap junction channel records. J Membr Biol 205:81-8
Valiunas, V; Polosina, Y Y; Miller, H et al. (2005) Connexin-specific cell-to-cell transfer of short interfering RNA by gap junctions. J Physiol 568:459-68
Christ, George J; Liebert, Monica (2005) Proceedings of the Baltimore smooth muscle meeting: identifying research frontiers and priorities for the lower urinary tract. J Urol 173:1406-9
Valiunas, Virginijus; Mui, Rickie; McLachlan, Elizabeth et al. (2004) Biophysical characterization of zebrafish connexin35 hemichannels. Am J Physiol Cell Physiol 287:C1596-604

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